IT Forensics · Courts
Is it possible to determine when a file was created or modified?
At first glance, timestamps appear straightforward. In practice, however, they are among the most commonly misunderstood digital traces. A file may contain several time entries, the meaning of which depends on the file system, operating system, application programme and transmission method.
For example, a copied file may retain its original modification date, whilst its creation date is reset on the destination system. Cloud synchronisation, ZIP archives, backups, email attachments or file recovery can also alter time stamps.
That is why we do not answer the question of when a file was created or modified on the basis of a single column in a forensic programme. We examine the time stamps in their technical context and look for independent evidence that either confirms or contradicts the alleged sequence of events.
The actual question of evidence
How is a file timestamp preserved for forensic purposes?
First, we determine which timestamps are actually available and what they mean from a technical perspective. We then compare file system data with document metadata, application traces, backups, snapshots, email or cloud context and, where applicable, logs.
If several independent sources are consistent in terms of timing, this may provide a reliable timeframe. If the sources contradict one another, this contradiction is not glossed over, but is investigated and explained in the expert report.
Where the limits of what can be said lie
A single timestamp does not, as a rule, prove either the identity of the person who modified a file or the specific action that led to that timestamp.
Why LanCologne?
In the case of court-ordered investigations, it is not a matter of which analysis programme displays a match first. What matters is whether the question of evidence can be answered on a technical basis and whether that answer stands up to independent scrutiny.
We adopt an open-minded approach, document the origin of key findings and examine alternative technical explanations. The actual analysis is always carried out on a forensic copy or a dataset that has been securely preserved as evidence. Originals are not examined directly unless absolutely necessary. Where live procedures are technically necessary, any changes that may result from them are explicitly documented.
Depending on the research question, key findings are verified either using a second method appropriate to the subject matter or directly on the basis of the underlying raw data. The tools used for this purpose depend on the evidence and the research question. The key factors are the suitability, professional recognition and traceability of the method – not a product name.
Our report distinguishes between factual findings, technical assessments and remaining uncertainties. A negative finding is justified just as carefully as a positive one.
How we handle court-ordered assignments
How we work – from the court order to the response
We first check whether the matter falls within our area of expertise, what facts the court is basing its decision on, and whether the content or scope of the assignment is clear. If there is any doubt, the court will seek clarification. This is in accordance with Sections 404a and 407a of the Code of Civil Procedure (ZPO).
Any reasons that might give rise to doubts as to impartiality are examined before the substantive investigation begins and, where appropriate, disclosed to the court.
Devices, data storage media, backups and files provided are identified and documented. The status at the time of the investigation is recorded.
Where technically feasible, a forensic copy or image is created. Hash values and other integrity checks are used to ensure unambiguous identification. The original is retained for future verification.
We determine which evidence would support the alleged event, what contradictory findings are conceivable, and which alternative technical explanations need to be examined.
Only those artefacts which have professional evidential value in relation to the issue in question are examined. Automatic matches are not accepted without verification.
Findings relevant to the decision are – where necessary – cross-checked using a second recognised method, a different technical approach or directly against the raw data.
We explicitly examine what conclusions must not be drawn from the data. We identify missing data, possible deletions, technical limitations, incomplete extracts or contradictory evidence.
The final conclusion is drawn from the documented findings. It is not stated in stronger terms than the data permit.
The main text remains accessible even to those without a background in digital forensics. The technical appendix contains the information required by an independent IT forensic expert to carry out a technical review or prepare a counter-report.
Legal framework
Sections 403, 404a, 407a and 411 of the Code of Civil Procedure (ZPO); Section 286 of the Code of Civil Procedure (ZPO). The expert provides the technical assessment; the court retains the power to evaluate the evidence.
The expert provides the factual basis for the case. The legal assessment and the final evaluation of the evidence remain the responsibility of the court.
Frequently Asked Questions
LanCologne – IT Forensics for the Courts
Do you require an independent technical investigation into a matter of evidence for court proceedings? LanCologne examines digital evidence objectively, transparently and in a reproducible manner. We document both positive findings and the absence of evidence, as well as technical limitations, in such a way that the conclusions remain comprehensible to the court and verifiable by an independent IT forensic expert.
Related to this topic
- Is it possible to determine whether a file has actually been opened or used?
- Is it possible to determine whether a file has merely been viewed or has actually been edited?
- How reliable are drafts, auto-save files and temporary documents?
- Can a file be associated with a specific programme used to create it?